A first hood member is fixed to an upper side opening edge of machine room and a second hood member is adjacently fixed to the upper side opening edge. The first hood member includes a reinforcing deformation part disposed along one notch-like edge portion positioned above a part adjacent to second hood member and has a protruded-shape cross section upward; and a pressing portion disposed at one notch-like edge portion along the reinforcing deformation part and protruding downward. The second hood member includes a pressed groove portion disposed corresponding to the pressing portion and has a recessed-shape cross section upward.